Araecerus fasciculatus: Coffee bean weevil

California Pest Rating for
Araecerus fasciculatus: Coffee bean weevil
Coleoptera: Anthribidae
Pest Rating: B

Initiating Event:

Araecerus fasciculatus has a current CDFA rating of B or Q. A pest rating proposal is required to assign a permanent rating.

History & Status:

Background: Araecerus fasciculatus is a small dome-shaped, dark brown beetle that is commonly known as coffee bean weevil (CBW). It is found in tropical and subtropical coastal countries where it is considered as a major pest of coffee beans, corn, cocoa, nutmeg and the seeds of leguminous plants4. It can consume any stored food that is not too dry. The larvae live and feed inside the coffee beans which causes them to turn rotten. The coffee bean weevil does significant damage above 28°C but it cannot complete its development from egg to adult at temperatures below 22 °C1.

The coffee bean weevil has long legs and the long antennae has three large segments on the end forming a club. The wings do not cover the entire abdomen leaving the last segment exposed. The body is covered in fine short hairs1.

In the early 1900s, the coffee bean weevil was considered primarily a stored product pest, as it generally infests a wide variety of stored food materials. However, from the 1920s onward, there have been reports that this pest also attacks living plants or fruits, especially soft, tropical fruits. The coffee bean weevil can attack papaya (Carica papaya), citrus, as well as assorted dried foodstuffs including dried fruits, nuts, mushrooms, herbs and spices, various palm seeds including (Phoenix dactylifera (date palm), Washingtonia filifera), sunflower (Helianthus annuus), Corn (Zea mays ), Nutmeg (Myristica fragrans ), Kava (Piper methysticum), Peanut (Arachis hypogaea), Taro (Colocasia esculenta), Sweet Potato (Ipomoea batatas), Rice (Oryza sativa), Hot peppers (Capsicum sp.), Yam (Dioscorea sp.), Bananas (Musa sp.), Ginger (Zingiber sp.) and Jujube (Ziziphus sp.)2.

Worldwide Distribution: The coffee bean weevil was originally described in 1775 from India, and it has been reported worldwide in tropical/subtropical regions (both in the field and in storage) 4. It has been reported in temperate regions only in heated facilities.  The coffee bean weevil is considered a minor pest of stored products in Asia and Australia. It has spread through many of the Southeast Asian countries and it is also present in Mexico, Belize, and Panama2.

In the United States coffee bean weevil is reported in Florida, Ohio, New Jersey, District of Columbia, Alabama, Mississippi, Texas and North Carolina. In California it was collected in a residential area of Orange County in 19944.

Official Control: The coffee bean weevil is listed as a harmful organism in Iran, Egypt, Guatemala and Panama 5.

California Distribution:  The Coffee bean weevil is probably established in Los Angeles and Orange counties; however, there have not been any recent surveys to confirm this.

California Interceptions: The coffee bean weevil was intercepted five times between June, 2002 to August, 2003 in Los Angeles and San Mateo Counties (PDR-1424722, 205694, 1253758, 1253707 & 1253892)3.

The risk Coffee bean weevil would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The coffee bean weevil can feed on a variety of stored products which includes most field crops and fruits of California. The coffee bean weevil may establish in larger, but limited, warm agricultural and metropolitan areas of California, as it cannot survive at higher elevations. It receives a Medium (2) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California: Score: 2

Low (1) Not likely to establish in California; or likely to establish in very limited areas.

Medium (2) may be able to establish in a larger but limited part of California.

High (3) likely to establish a widespread distribution in California.

2) Known Pest Host Range: The coffee bean weevil has a wide range of hosts and it can feed on almost 100 different kinds of stored products4.  Host species are grown throughout California.  It receives a High (3) in this category.

Evaluate the host range of the pest: Score: 3

Low (1) has a very limited host range.

Medium (2) has a moderate host range.

High (3) has a wide host range.

3) Pest Dispersal Potential: Each female lays up to 60 eggs and the larvae emerge in 5 to 20 days. The entire life cycle can take as little as 21 days or as long as 80 days, depending on environmental conditions.  The coffee bean weevils are strong fliers and can fly long distances. It receives a High (3) in this category

Evaluate the natural and artificial dispersal potential of the pest: Score: 3

Low (1) does not have high reproductive or dispersal potential.

Medium (2) has either high reproductive or dispersal potential.

High (3) has both high reproduction and dispersal potential.

4) Economic Impact: The coffee bean weevil is well-known for causing significant damage to stored agricultural products, especially those in warm storage. The tiny, grub-like larvae bore their way into any seeds or beans and excavate a cavity. Several larvae feed on each bean and end up consuming a considerable portion; this decreases the crop value. It receives a Medium (2) in this category

Evaluate the economic impact of the pest to California using the criteria below:  

Economic Impact:  B, C

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

Economic Impact Score: 2

Low (1) causes 0 or 1 of these impacts.

Medium (2) causes 2 of these impacts.

High (3) causes 3 or more of these impacts.

5) Environmental Impact: The coffee bean weevil is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not expected to directly impact threatened or endangered species. It can increase production costs to growers if they perform any treatment to control infestations. It is not expected to have significant impacts on cultural practices, home/urban gardening, or ornamental plantings. The coffee bean weevil receives a Medium (2) in this category.

Evaluate the Environmental impact of the pest to California using the criteria below:  

Environmental Impact:  D

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Environmental Impact Score: 2

Low (1) causes none of the above to occur.

Medium (2) causes one of the above to occur.

High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Coffee bean weevil:  Medium (12)

Low = 5-8 points

Medium = 9-12 points

High = 13-15 points

6) Post Entry Distribution and Survey Information: The coffee bean weevil has been intercepted five times since January, 2000. It was reported   in Orange and Los Angeles counties in 1994 &1995  It receives a Low Score (-1) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included: Score -1

Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (11)


No detection surveys have been conducted recently. Because the host material the Coffee bean weevil attacks is found throughout California, it could easily spread and become established.

Conclusion and Rating Justification:

Currently the coffee bean weevil is only known from Orange and Los Angeles Counties, but it could become established and spread. It has the potential to have limited economic and environmental impacts. A “B” rating is justified.

  1. Australia Wildlife site Oz animals .com   Accessed on 12-6-16.
  1. Entomology Laboratory, Institute of Plant Breeding, College of Agriculture, University of the Philippines. Accessed on 12-6-16.
  1. Pest and Damage Record Database, California Department of Food and Agriculture, Plant Health and Pest Prevention Services.
  1. Pest and Damage Record Database. CPPDR report 1996. Accessed on 12-6-16.
  1. USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed on 12-6-16.
Responsible party:

Javaid Iqbal,  California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 403-6695;[@]

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Pest Rating: B

Posted by ls